The objectives of the present research are to (1) investigate synthesis, transformations, and the mechanistic properties of heterocyclic diazo compounds, related triazenes, and N-nitrosoureas of present importance in cancer therapy, (2) prepare and determine the properties of new diazo compounds, diazirines, diaxotates, and azoxy compounds of possible value in oncology, and (3) provide experimental quantities and/or laboratory methods for various agents so that their antineoplastic properties can be determined. The study will include investigation of (1) synthesis and properties of 4- and 2-diazoimidazoles, 3- and 4-diazopyrazoles, 4- and 5-diazotriazoles, 2-and 3-diazopyrroles, diazotetrazole, and their derivatives, (2) generation and the chemistry of diazodihydropyridines, diazothiopyrans, their analogs, their hetarylidenes, and related novel pyrylium, thiopyrylium, and pyridinium derivatives, (3) 3, H-diazirines, 3,H-diazirine-N-oxides, and their analogs, and (4) 3-alkyl-1-(haloalkyl)-1-nitrosoureas, various substituted and unsaturated diazotates, and related unsaturated and functionally-substituted azoxy compounds.